Questions about alchemy

Hello guys, I have a lvl 90 rogue with 600 herbalism, and I was thinking about leveling alchemy with it as well, so my questions are:
1. I don't have the patience to level alchemy to 600, is it easy? or should I buy mats on AH and once I get to 600, will i get back that money I spent for the mats easily?
2. I heard about Elixermaster/Potionguy:P/Transmute, I hear that Transmute is the best for gold.. is it easy to get gold with it, and I don't really know what mats a transmute uses and what he makes :P kind of a noob in these stuff.
Thanks guys

It's mostly easier to buy it off the AH except for a few hard to find ones that are prohibitively expensive. I have multiple alchs so that I can make whatever I want. Each has procs so each can make money.

In my experience transmutation master was the least profitable. Transmuting diamonds was ok but the mats were often more than the diamond was worth and selling them was tough as the gem market fluctuates very fast. Truegold/living steel xmutes only happen once a day, so you wont see too many mastery procs. Unless you burn harmonies on it but thats often a net loss vs the value of 3 harmonies.

Potion mastery is pretty good. You can make an aweful lot of pots with very little invested in buying herbs. Since pots require the least mats to make, you will craft lots of them and get a ton of mastery procs, netting you even more pots. However then you need to sell (literally a thousand) potions. That can take long time.

Personally, ive settled on elixir mastery. I can sell the flasks and elixirs i make with the least effort, and every time you get a X3 or X4 flask proc it means free (on my server) 500-600 gold. Thats a nice bonus you will see every crafting session.

Guys please help :P, if I learn transmute or elixir, can i Learn something else instead another time?
and another thing.. If i don't have JC, is transmute still more profitable? or should i get elixir master?

On most servers lower lvl herbs are going for high amounts of gold, so herbing or farming mats yourself to sell leftovers is worth it, and i think once you get to WoTLK content and mats leveling speeds up a lot

Guys please help :P, if I learn transmute or elixir, can i Learn something else instead another time?
and another thing.. If i don't have JC, is transmute still more profitable? or should i get elixir master?

You can talk to the trainer and unlearn one and learn another. Transmute is still good for the once a day living steel but that's one thing a day. Elixir you can do all the time. Transmutes gold value comes from getting extra meta gems after your JC shuffle (they sell around 200-1000g depending on server)